CONTROL OF THE MILK SUPPLY 227 



sumed fresh it should be r nfri<jerated, i.e. kept at a temperature 

 below 4 C., for this inhibits the rapid multiplication of bacteria. 

 When milk cannot be used fresh or refrigerated, it should be sterilised 

 by heat. 



3. Greater domestic and municipal cleanliness is an essential 

 requirement. This must include the cleanly preparation of food, 

 and particularly the handling and storage of milk; the cleansing 

 of milk-bottles; reduction of dust in houses, courts, and streets, 

 and protection of milk from dust in shops and houses ; impervious 

 roads and paving; and the substitution of wet-cleansing for dry 

 cleansing, and frequent cleansing for infrequent. 



4. Lastly, there is needed "a crusade against the domestic fly, 

 which is most numerous at the seasons and in the years when 

 epidemic diarrhoea is most prevalent, and probably plays a large 

 part in spreading infection " (Newsholine). 



METHODS OF PROTECTING AND PURIFYING MILK 



After the consideration of the somewhat extensive category of 

 diseases which may be milk-borne, it will be desirable to make brief 

 reference to some of the means at our disposal for obtaining and 

 preserving good, pure milk. 



We considered at the commencement of this chapter the most 

 frequent channels of contamination. If these be avoided or pre- 

 vented, and if the milk be derived from cows in good health and 

 well kept, the risk of infection is reduced to a minimum. The two 

 things necessary are clean, healthy cows and clean methods of milking 

 and manipulation. What the Danes can do, other dairy workers 

 can do. The cow byre, the udder, the milk vessel,* and the milkers 

 should each be thoroughly clean.f But we have seen that much, 



* Probably the best method of cleansing dairy utensils is by using steam or 

 boiling water and soda. The advantage of boiling water is obvious. The addition 

 of soda enhances its value, as the soda unites with the lactic acid present, forming a 

 soluble lactate of soda, and also with grease, a fat forming an easily soluble soap. 

 Nor does it injure or rust the metal with which it comes into contact. 



f It may be well to add in a footnote an account of the Danish method as 

 carried out in England, for it illustrates in concrete form the practical way of 

 reducing pollution of milk to a minimum : 



The principles and practice of the Copenhagen Milk Supply Company have 

 been introduced into England, and are being carried out by Mr C. W. Sorensen 

 at the White Rose Dairy, West Huntington, York. Mr Sorensen is a nephew of 

 Mr Busck, of the Copenhagen Company, and has been trained in the Danish 

 methods. His dairy farm at York is carried on in a similar manner to the 

 Copenhagen Company's work, with this difference, that whilst the latter obtain 

 their milk from contributory farms, Mr Sorensen works his own farm, and the 

 control and management of the cows is under his direct and immediate supervision. 

 The writer had an opportunity recently of visiting this dairy farm near York, and 

 a brief description of the most important points may be added here. 



1. The health of the cows is secured by a special monthly inspection by the 



